Physical Properties

Material GaAs InP GaN
Crystal structure Zinc blende Zinc blende Wurtzite
Lattice constant (300K) 5.654 Å 5.869 Å

(a) 4.189 Å

(c) 5.125 Å

Atomic density (300K) 4.43 ×10²² cm⁻³ 3.96 ×10²² cm⁻³ 8.9 ×10²² cm⁻³
Melting point 1238 °C 1060 °C 2500 °C
Density (300K) 5.315 g cm⁻³ 4.81 g cm⁻³ 6.15 g cm⁻³
Linear thermal expansion coeffi cient (300K) 6.03 ×10⁻⁶ K⁻¹ 4.60 ×10⁻⁶ K⁻¹

(a) 5.59 ×10⁻⁶ K⁻¹

(c) 3.17 ×10⁻⁶ K⁻¹

Thermal lattice conductivity (300K) 0.48 W cm⁻¹ K⁻¹ 0.68 W cm⁻¹ K⁻¹ 1.3 W cm⁻¹ K⁻¹
Specific heat (300K) 0.325 J g⁻¹ K⁻¹ 0.31 J g⁻¹ K⁻¹ 0.49 J g⁻¹ K⁻¹
Energy gap (300K) 1.42 eV 1.344 eV 3.39 eV
Electron mobility (300K) 8800 cm² V⁻¹ s⁻¹ 5400 cm² V⁻¹ s⁻¹ 1000 cm² V⁻¹ s⁻¹
Hole mobility (300K) 450 cm² V⁻¹ s⁻¹ 200 cm² V⁻¹ s⁻¹ 200 cm² V⁻¹ s⁻¹
Effective electron mass 0.068 m₀ 0.08 m₀ 0.20 m₀
Elastic constants
C11
C44
C12

11.88 ×10¹⁰ Pa
5.49 ×10¹⁰ Pa
5.38 ×10¹⁰ Pa

10.11 ×10¹⁰ Pa
5.61 ×10¹⁰ Pa
4.56 ×10¹⁰ Pa

29.6 ×10¹⁰ Pa
2.41 ×10¹⁰ Pa
13.0 ×10¹⁰ Pa
Mohs hardness 4.5 4.0 8.0
Vickers hardness for (0.05 .. 1) N 6.52 ×10⁹ Pa 3.94 ×10⁹ Pa 10.2 ×10⁹ Pa